bind 9 - wrong domain name resolution

[Leovino A. Trinidad, Jr]

Hi!

We had this problem which is kind of weird. The DNS linux box was setup almost 2 years now and just recently we received this error. When we tried to nslookup an internal domain name (typed in the dns box) it shows us the equivalent public IP of the domain instead of its private IP. But when we restart the dns box the naming lookup returns to normal.

I don't know where the problem is but I just have a hunch that it came from our Internet Load balancer that was installed recently (3 ISPs connected).

Can you help me verify and resolve this problem?

Thank you in advance.

Regards,



LAT

[Alexander Chuzhoy · Accepted solution]

First see inside /etc/resolv.conf
who is the nameserver (dns server) of your dns.
Then see the configuration of the dns that appears in /etc/resolv.conf

If you want it only to resolve internal IP addresses-I'd remove the entry of zone "."
from /etc/named.conf

[xyko_1]

Hi,

I think it's about route resolution. As I can undestand about your problem, your dns server has two or more network interfaces, one for internal lan and another for external access (internet). You have to verify if there are any problems concerded with the route to access the dns server. When the wrong name resolution happens, verify the route from your workstation to the dns server (tracert in windows, traceroute in linux) and see if it's ok. Then restart the dns server (the name resolution, as you say, will be ok) and traceagain.

I thnk you will be able to determine a routing problem in your network.

Hope it helps.

Regards,
Xyko

[Johannes Krackowizer_1]

hi,

do you use dial-in to connect to the internet? if it is so you properly have some scripts for making the connection, setting the routing table, ... and the change also /etc/resolv.conf. in this file are the entries which dns-server ask first, second, third if you put your own dns server to the first position then your own dns database is asked for name resolution otherwise the dns-server of your isp is asked to answer the dns questions and your isp knows only your external ip.

Johannes

[Steven E. Protter]

With three ISP's coming in that gives you three possible outside sources for errors in DNS information.

The key is /etc/resolv.conf

You may want to run some tests seeing if you can ping those servers and commenting all but one out and making sure all three are providing good dns information.

It also could be an internal server, depends on resolv.conf

I would also urge you to check this link:
http://forums1.itrc.hp.com/service/forums/pageList.do?userId=BR732737&listType=unassigned&forumId=1

and get caught up on point assignment.

SEP

[Leovino A. Trinidad, Jr]

Hi guys!

Thank you for all of your responses. I think there is nothing wrong with our resolv.conf the items that are listed are, by order: localhost, ISP DNS1 and ISP DNS2. The DNS server is used for mail relaying as well as for Internal and Internet address lookup. The problem just occured when our load balancer came up, hosting 3 different ISP links. Maybe I will try if the problem occurs again the arp static mapping in the load balancer.

Also, thank you SEP for reminding me about unpointed cases, I am not aware that I should give points to everybody who participates in solving the case. I thought points are only given to those who possibly resolved the problem.

Again, thank you and regards.


LAT